Dehydrating apparatus



Aug. 28, 1928.

W. D. CALLAN DEHYDRATING APPARATUS 1920 5 Sheets-Sheet Original Filed May 5 Aug. 28, 1928.

W. D. CALLAN DEHYDRATING APPARATUS Original Filed May 5, 1920 5 sheets-sheet 2 Aug. 28, 1928.

W. D. CALLAN DEHYDRATING APPARATUS \L a mh m NB Nb Aug. 28, 1928.

W. D. CALLAN DEHYDRATING APPARATUS GUN MM u. M. M w N MW @fvwm Original Filed May 5 latented Aug. 28, 1928. l

UNITED STATES PATENT OFFICE. A

WILLIAM D. CALLAN, F DULUTH, MINNESOTA, ASSIGNOR T0 ECONOMIC POWDERED PRODUCTS COMPANY, OF MINNEAPOLIS, MINNESOTA, A CORPORATION 0F DELA- WARE.

DEHYDRATING APPARATUS.

Application led May 5, 1920, Serial No. 379,026. Renewed July 5, 1927.

My invention relates to apparatus for removlng the Water contained in milk, and other' similar fluids, and collecting the residue or basic substance in a powdered, granular or other form. The object of my invention is particularly to provide an apparatus that y will be sanitary, etlicient, and of large capacity for condensin and powderin milk, and that will be simp e of construction and require but little attention in operation.

My invention consists generally in, improvements in atwo stage process of dehydrating milk or other fluid viz' By iirst directing and, distributing, Within suitable cells, opposing currents of heated air lnto a spray or nii-ist of the liquid, produced in the cells, absorbing the largest portion of the Water by the air currents, and settling the condensed fluid by preci itation and gravita tion into suitable condlilctors; and second, by presenting the same rocess with the condensed fluid, to absorb t e remaining portion of the water by the heated air, collect the dried or'powdered basic substance of the fluid by precipitation, and separate any remaining rcentage of the substance from the air be ore it is discharged from the cell.

My invention consists in certain constructions and combinations as will hereinafter be described and particularly pointed'out in the claims. l

In the accompanyingdrawings, formlng I y part ofthe specification,

Figure 1 is al longitudinal vertical section, with parts in elevation, of a condensing and powdering apparatus constructed according to my invention.

Figure 2 is a lon itudinal horizontal section, with parts in e evation, on the line 2-2 of Figure 1,

vFigure 3 is a similar section, with parte 1n elevation, on the line,33 of Figure 1,

Figure 4 is a vertical cross section of the condensing cell, with parts in elevation, taken on the line 4-4 of Figure 1,

Figure 5 is a horizontal section on the line 5-5of Figure 4,

Figure 6 is a' vertical section on the line 6-6 of Figure .2, illustrating the Way in which the hot air currents, for evaporating and carryin away the moisture inthe milk, enter the de ydrating chambers.

Figure 7 is a plan sectional view on the line 7-7 of Figure 6 through one of the air distributing ducts by which the air enters the dehydrating chambers.

Figure 8 is an end elevation of the dust shown in Figure 7,

Figure 9 is a sectional detail view.

In the drawings A represents the primary condensing cell, in which about two thirds of thev Water is removed from the milk, and B is the final drying and powdering cell of the basic milk product. The cells A and B are shown to b e of the same size and it will be understood that one owdering cell ordinarily has sufficient capac1ty to finish the product from two condensing cells of the same size, one of which is shown on the drawings. The cell structure is erected preferably on a concrete floor foundation 12 and consists of the side walls 13 and 14 extending from the floor 12 to the ceiling 15, the lower cross walls 16 and 17, and the upper cross Walls 18, all of said cross Walls joining the side walls 13 and 14. VThe upper cell compartments A and B', bounded by the walls 18, are shorter that the lower compartments of the cells and transverse girders 19 upon Awhich the upper walls 18 rests are embedded in the side walls 13 and 14. Intermediate floorsections 20 and 21 are supported by the girders 19 and connect the lower cross walls 16 and 17 to the upper cross walls 18. The end cross wall 16 extends from i the loor to the ceiling and an outer end wall 22 spaced from the wall 16 forms an air space 22l along the cell B, and an outer wall 23 spaced from the side wall 13 forms a longi-l tudinal closed passage 23". The Walls are preferably constructed of hollow tile or other material impervious toheat, and are preferably covered with a non-heat conducting sheet 24 of asbestos or' other similar material. The upper cell compartments are identical in construction and are provided with the vertical walls 25 extending diagonally7 from the side to the cross walls across each corner ofthe cells, and having bottom plates 25, thus transforming the cells from a rectangular to an octagonal form and providing a closed triangular chamber 26 in each corner of the cells. Through these chambers pass vertical air conductors 27, communicating with horizontal branch `ducts 29 and 30 coming from the main trunk ducts31al and 31. The air conductors 27 branch oif in curved or goose neck nozzles 32, 33 and 34, (see Figures 6 to 8) preferably pointing slightly downward-S and towards the center of thecells and being provided with discharge openings 35, leadmg through the diagonal walls 25. The nozzles 32, 33 and 34, branching off from the conductors 27, increase in area from the bottom upwards and are provided with a curved baille plate 36 and a series of partitions 37 for the purpose of breaking up and diverting the air stream into a series of distributing and eddying currents of air. The nozzles preferably have Haring discharge ends .38 from which the air currents emerge in diierent directions converging generally from opposite sides to the-center o the cell and in a downward direction.

- It will be understood that the air is first heated to a certain temperature and inducted under suitable pressure through the trunk ducts 31 and 31b and branch duct-s 29 and to the distributing conductors 27 and 28 by means not disclosed in the drawings as these means form no part of the present invention. Through the ceiling 15 of the cells which generally constitutes the working floor of the plant, and in the center of the upper cells A and B are projected the sprayers 40A and 40B which may be of any suitable con` struction but preferably consist of a series of slightly separated annular .spraying plates provided with holes and connected to a hollow rotating shaft 41 through which the fluid enters to the spraying plates. Driving pulleys 42 driven from any suitable, as electric motors 42a and 42", are provided for the shafts 41 and supplypipes 43A and 433 hav- 111g regulating valves 44^ and 44B, deliver the Huid to the hollow shafts 41. Below the upper cell compartment A is attached a convergin hopper 45 having a central constricte opening 46 throu h which the vaporized fluid, broken up an thoroughly mixed with air into a saturated vapor, enters the lower condensin chamber or compartment of cell A. A gat ering hopper 47 having an outlet 48 is supported on the side walls 13 and 14 some distance below the hopper 45, leavin an open air space 471 forming a horizontal y extendingrestricted air passage between the two hoppers and air. spaces 48 between the hopper 47 and cross walls 16 and 17. Closely woven fabric or screens 49 (see Figures 1, 4 and 5) supported vertically in suitable frames 50 are secured to two sides of the hop er 47, to the floor 12 and side walls 13 and 14 `means of angle bars 51 and 52, and a simi ar screen 49 is secured in an o ening 53 in the wall 13 below the hopper 47. The moisture laden air coming in large volume from the upper' compartment cell A and passingthrough therrestricted opening 46 inthe hopper 45, ves off the heavier,'or more saturated portion of the vapor, containing the basic ,fluid substance, which condenses and settles by precipitation, and gravity to the bottom of the hopper 47 where it l is collected and carried away by an inclined trough 54. The water laden air freed from thevheavier material is compelled to pass out between the hoppers 45 and 47 through the air space 47 a downwards through the air spaces 48, through the screens 49 and screens 49:l to the passageway 23 as indicated by the arrows. In its passage downwards and through the screens the water is given off and, collecting on the concrete floor of the cel1,"is run oil in any well known manner not shown. Any condensed fluid that may collect on the screens 49 and 49". gravitates to the troughs 541 and 54", from which it mayy be periodically drained off and saved. The proportion of moisture removed from the milk or other fluid by this process is substantially about of the total water contents of the fluid, and the condensed iuid is then discharged from the trough 54 into a. container 54c from which it is pumped to the sprayingr apparatus 40B in the final dehydrating and powdering cell B as will hereinafter be more particularly described. Below the upper dehydrating compartment of cell B and spaced below the floor sections 20 and 21, (see Figures 1 and 3) are mounted plates or sheets 55 and 56 joining the side walls 13 and 14,

and inclined towards the center of the cell,

terminating in a hopper 57 in which is mounted a spiral conveyor 58. Similarly inclined apron conveyors 59 and 59 are mounted on.

rollers 60 and 61, and driven in the direction of the arrows in Figures 1 and 3. These rollers as well as the conveyor 58 are journalled in suitable bearing brackets in the side walls 13 and 14 and are driven from any suitable source of power by means of a driving pulley 60, gears 61a and sprocket wheels 62, 63 and 63 and chains 64 and 65. The conveyor 58 is driven from the roller 60 by sprocket wheels 58 and 59 and chain 58". Vertical screens 66 and 67 are attached to the sheets 55 and 56 and walls 13 and 14 substantially as in cell A and a screen (not shown) corresponding to the screen 49 in this cell is secured in the wall 13 belowthe conveyors. The screens 66 and 67, instead of being secured directly to the floor are connected to the casing of spiral conveyors 68 and 69. attached to the floor and inclined gathering shields 70 and 71 are attached to the conveyor casings and to the cross walls 1G and 17. The shields and conveyors extend the full width of the cell and the conveyors extend through the side wall 14 outside of which they are preferably provided with operatinghandles 72, (see Figure 3). As the condensed milk emerges from the sprayer 40B inthe linal deh drating and powdering compartment of ce l B, a mist is .formed in the upper compartment B of cell B and the hot air currents, streaming into the chamber from opposite directions thorough absorb the remaining moisture in the mi in the form of a steam and separates the water completely from the basic milk product ywhich gravitates and falls upon the conveying aprons 59 and 59'Ll in the form of a dry powder. The moist hot air passes outwards and downwards through the air spaces 73 and 74, the screens 66 and 67 and a screen similar to 49a in cell A, to the passa-ge 23a.

aprons 59 and 59 will be conducted to the conveyor 58 by which it will automatically be conveyed out of the cell. In the. operation' of a complete milk dehydrating plant the milk is first delivered to a receiving tank or container 75 (see Figure l) arranged upon the floor l2 of the plant which floor is preferably below the ground line and in the basement of the plant. A sanitary pump 76, which may be of the rotary or any other type and may be driven by means of a pulley 77 elevates the milk from the tank 75, through pipes 78 and 79 to the supply pipe 43A for the sprayer 40A. The motor or engine (not shown) driving the pump 76 is provided with a suitable pressure governor, which maintains a uniform pumping pressure in the pipe 79, and to further provide a reserve against possible iuctuatio'ns in the pressure and assure uniformity lin the delivery of the milk to the sprayers, Ipprovide a regulating reservoir 80A (see Figure 9) above the inlet to the Sprayers. This reservoir consists preferably of a nipple 81 in which is screwed a vertical pipe 82, having a cap or cover 83 with a valve 84 for escape of air when the dehydrating operation is commenced. At .the bottom the pipe nipple 81 terminates in a hoppered settling chamber 85, closed at the bottom with a removable cap 86 and just above the settling chamber 85 are connected the horizontal inlet pipe 79 and the horizontal pipe 43A supplying the sprayer 40A. A deflecting plate 87, directing the incoming stream of milk upwards in the pipe 82, from the inlet pipe 79 is arranged above the'settling chamber 85. The capacity of the pump 76 is normally greater than the capacity of the condensing cell and when the condensing operation is started, the reservoir 8OA at first being empty will gradually fill and as much of the air as may be desired may be let out of the reservoir bv opening the valve 84.

. This valve is then closed andthe milk flowing in from the pipe 79, circulates upward Y and downward through the reservoir 80A and 40A, regulated in volume by the valve 44A. Any foreign matter will gravitate to the settling chamber 85, from which it may be periodically removed by` the operator. It will be understood that thepressure governor on the motor regulates the fiow of milk to the reservoir 8()A and keeps it under a certain pressure and any possible fluctuations will be taken up and compensated for by the reservoir fluid in the pipe 82 aided by the cushioned air above the Huid in the pipe. The condensed milk from lower compartment of cell A discharging into the container 54C is drawn from this container and elevated, through pipes 88 and 89, to the sprayer 40B of the linal dehydrating cell B, by means of a pump 90 similar in function to the pump 76. The milk, in its fiow to the sprayer 40B passes through a regulating reservoir-8WB similar in construction and function to the reservoir 8() and as the milk emerges from this reservoir it passes through the supply pipe 43B and regulating valve 44B to the sprayer 40B and into the dehydrating chamber B for the final dehydrating operation as heretofore described. The air from both the condensing and powdering cell A and B, passing from the cells into the passage 23a escapes from this passage to the outer atmosphere through suitable ventilators 91 arranged at intervals at the top ofthe passage. It is evident that various modifications may be made in the details of construction of the apparatus without departing from the principle and scope of the invention and I do not therefore confine myself strictly to the construction as shown.

I claim as my invention:

l. A dehydrating cell for fluids comprising an upper and lower compartment, means for directing currents of heated air into said upper compartment, a fluid sprayer in said upper compartment, said cell having a horizontall extending restricted air passage from t e lower portion of said upper comartment to said lower compartment, colecting means below said passage and air ducts passing downwardly around said collecting means and connected with said restricted passage. v

2. A dehydrating cell for milk or other iuids comprising an upper and a lower compartment, means for directing currents of eated air into said upper compartment, a iuid sprayer in said upper compartment, said cell having an air passage from the up er to the lower compartment, between the a jacent ends of the two compartments, collecting means below said air passage, air ducts around said collecting means, screens below said collecting means throu h which the air passes from said ducts, an means for collecting the material separated from the air by said screens. v

3. A dehydrating cell for fluids comprising an upper and lower compartment, means for directing currents of heated air into the upper compartment, a liquid sprayer positioned to deliver a spray into the path of the currents of heated air, said upper and lower compartment having a constricted passage between them at thelr adjacent ends, a hop er deviceV beneath said constricted passage or rece1v.

ing the condensed materia an air circulating above said hop er evice for receiving the currents of air rom said constricted passage, and means beneath said hopper device for screening said currents of lair.

4. In an apparatus for dehydrating lluids, a powdering cell, means for spraying material in the upper portion thereof, means in the upper portion ofthe cell for delivering currents of heated air into the spray of the material to be powdered, a table mounted in the lower portion of said cell and inwardly and downwardly inclined, a conveying means communicating with the inner portion of said table, gathering belts operating over said table for delivering the powdered material to said conveyor,`the currents of air'from the from said passage,

assage being provided upper portion of said cell owing downwardly and over the belts, and means positioned below the plane of the belts for screening said currents of air.

5. In an apparatus for dehydrating fluids, a cell, means for spraying material in the upper portion thereof, means in the upper portion of the cell for delivering currents of heated air to a spray of the material to be powdered, a table mounted in the lower portion of said cell and inwardly and downwardly inclined, a conveyer for receiving the material positioned at the lower end of said table, gatheringmeans operating over said table, a passage being provided above said table for the currents of air flowing from the upper portion of said cell, screens arranged below said table for screening said currents of air, and means for collecting the material separated from the currents of air by said screens.

In witness whereof,-I have hereunto set` my hand this 29th day of April 1920.

WILLIAM D. CALLAN. 

